As shown in FIGS. 1 and 2, an existing bearing comprises an outer ring 1, an inner ring 2, a number of rollers 3 accommodated between the inner and outer rings, and sealing structures 4 which perform a sealing action on two sides, in the axial direction, of the bearing. The sealing structure 4 comprises an accommodating member 41 fixed to an outer surface of the inner ring 2, a support 42 fixed to an inner surface of the outer ring 2, and a sealing member 43 connected to the support 42. The accommodating member 41 comprises a first axially extending part 411 held securely to the outer surface of the inner ring 2 in the axial direction, a second axially extending part 412 located on a radially outer side of the first axially extending part 411 and spaced apart from the first axially extending part 411, and a radially extending part 413 connecting the first axially extending part 411 to the second axially extending part 412. The first axially extending part 411, the second axially extending part 412 and the radially extending part 413 enclose an accommodating chamber 44 which is open towards the interior of the bearing. The sealing member 43 partially extends to the accommodating chamber 44, and specifically comprises a first sealing lip 431 extending towards the first axially extending part 411 and a second sealing lip 432 extending towards the second axially extending part 412, wherein the first sealing lip 431 is in contact with the first axially extending part 411, thereby forming a contact seal, and a radial gap is present between the second sealing lip 432 and the second axially extending part 412, thereby forming a gap seal. Furthermore, the sealing member 43 also comprises a third sealing lip 433 extending axially, the third sealing lip 433 being located outside the accommodating chamber 44, specifically being located on a radially outer side of the second axially extending part 412 and forming a gap seal with the second axially extending part 412.
The existing sealing structure 4 is too large in the axial direction, and correspondingly, the axial dimension of the inner ring 2 must also be increased; this will make bearing installation inconvenient in application scenarios in which the installation space is relatively cramped. In addition, during use, external dirty water, greasy dirt or particulate impurities easily enter the accommodating chamber 44 through the gap between the third sealing lip 433 and the second axially extending part 412, and are not easily flung out during bearing operation. At the same time, lubricating oil in the bearing also readily enters the accommodating chamber 44, and this easily leads to early failure of the sealing member 43.
Thus, there is a need to provide a new sealing structure to solve the abovementioned problem.